PHOMMANITH , K.; OUNKEO, C.; BOUSITH , O.; KEOPHASITH, V. A Study Mathematics Achievement by Using Problem-Based Learning for Grade 1 Students. Souphanouvong University Journal Multidisciplinary Research and Development , [S. l.], v. 7, n. 1, p. 70–78, 2021. Disponível em: http://www.su-journal.com/index.php/su/article/view/98. Acesso em: 17 jan. 2026.